In order to assure sound maintenance of pipes for transporting a fluid, it is essential to prevent surface corrosion as well as damage due to roadwork, etc.
For prevention of surface corrosion, a polyethylene lining for a layer covering the peripheral surface of a steel pipe, has recently been employed, thereby improving greatly the insulating performance or corrosion proof characteristic. Additional provision of electric anticorrosion assures prevention of surface corrosion.
However, damage to a steel pipe due to roadwork etc. on the road surface may cause a leak to occur, resulting in an accident. In order to prevent an accident, the managing agent of a buried object is required to perform extensive monitoring and management tasks such as by patrolling around the buried object or by being present at roadwork performed nearby the buried object. In this connection, immediate detection of pipe damage caused for some reason may help and assist such management, and is very effective for avoiding an accident.